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Biomedical subjects

E Schuller

Publications and source records attributed to E Schuller.

At least 73 records · Page 4Linked to original sources
PubMed1987

[Prevalence of anti-HIV antibodies in immunoglobulins recipients].

Seven hundred and forty subjects who, between 1980 and 1985, had received intravenous or intramuscular injections of immunoglobulins (Ig) prepared by Cohn fractionation of plasma pools from more than 2000 donors were investigated for anti-HIV antibodies. Anti-HIV antibodies were detected in only one subject, a female drug addict and therefore belonging to a group at high risk of AIDS. In contrast with the huge amounts of Ig received by the remaining 739 subjects (976 litres intravenously, 128 litres intramuscularly), this young woman had only received 10 ml of anti-HBs Ig intramuscularly. The wide scattering in both space and time of these recipients of Ig and the prevalence of anti-HIV antibodies among blood donors in France (0.7 per 1000 in 1985) suggest that all the batches studied (over 100) were contaminated by HIV. The absence in these subjects of seropositive reaction ascribable to the injections of Ig confirms that Cohn fractionation inactivates the virus, as demonstrated in vitro. It is concluded that recipients of Ig prepared from plasma pools not tested for the absence of anti-HIV antibodies should not be regarded as a group at risk of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Specific RNase isoenzymes in the human central nervous system.

After inactivation of RNase inhibitor by parachloromercuribenzoate, total alkaline RNase activity was found to be two fold higher in white matter as in grey matter extracts from human brain tissue. This activity was lower in human purified myelin. Two human cerebrospinal fluid (CSF) RNase isoenzymes of group 3 (a minor one, RNase 3.1, and a major one, RNase 3.2) were found to be present in human grey and white matter extracts and in purified myelin, but absent in human serum, peripheral nerve, liver, and spleen extracts. A RNase isoenzyme similar to central nervous system (CNS) RNase 3.2 was present in human kidney extracts but it differed in its carbohydrate structure. RNase isoenzymes 3.1 and 3.2 were not found in mouse, rat, and bovine brains. Thus, RNases 3.1 and 3.2 seem specific to human CNS. RNases of group 3 are the predominant RNase isoenzymes in CSF and one of the two predominant RNase groups in brain tissue. However, the proportion of RNases of group 3 is different in CSF and in brain extracts: RNases 3.1-3.2 are the major constituents of group 3 RNases in brain tissue, while another RNase isoenzyme of group 3, RNase 3.0, which is more glycosylated than RNases 3.1-3.2, is only a minor part of RNase of group 3 in brain extracts. Conversely, RNases 3.1-3.2 are lower or equivalent to RNase 3.0 in control CSF since the ratio of RNases 3.1-3.2 to RNase 3.0 did not exceed 1.0. This ratio decreased in pathological CSF including multiple sclerosis or infectious CNS diseases that were free of transudation phenomena. In conclusion, CSF RNases 3.1-3.2 seem to originate in brain tissue and could be markers of RNA catabolism from brain cells.

Animals↗
PubMed1987

Serum and CSF humoral immunity in Guillain-Barré syndrome: clinical correlations.

Paired samples of CSF and serum obtained from 29 patients affected with Guillain-Barré syndrome (GBS) were analyzed for various protein levels, including immunoglobulins and complement components. An attempt was made to correlate these findings to the clinical stage, severity, and duration of the disease. Intrathecal IgG synthesis was detected and quantified by means of a previously reported formula. It is practically constant in the GBS during the stage of stabilized paralysis, and is significantly greater in this stage than in the stage of progressive paralysis. Moreover, it increases with severity and duration (longer than 3 months) of the disease. Evidence of intrathecal C3 consumption is also presented.

Adolescent↗
PubMed1987

[Immunity and catabolism of nucleic acids: the problem of multiple sclerosis?].

In multiple sclerosis (MS), exogenous or endogenous nucleic acid fragments not (or partially) catabolised inside central nervous system (CNS) could entertain an inflammatory and even demyelinating process, and delay resynthesis of myelin. So, exogenous nucleic acids could act as starting agents for acute phase. Nucleic acid material can be released by the enzymes of nucleic acid catabolism and by the antibodies to nucleic acids possibly synthesized. A preliminary approach of such hypothesis has been made by study of cerebrospinal fluid ribonuclease activity and intrathecal synthesis of antibodies to nucleic acids. These two factors are significantly different in MS and in infectious processes of CNS groups. According to our hypothesis MS could arise from a genetic defect of oligodendrocyte (ODC) acting in genome expression and consequently leading to the persistence of nucleic acid fragments. This defect of ODC might be associated to another immune defect explaining various evolutive forms of the disease.

Antibodies, Antinuclear↗
PubMed1987

[Demyelination in in vitro culture in multiple sclerosis: facts and controversies].

The myelinotoxicity of sera from multiple sclerosis (MS) patients was determined by the assessment of visible myelin damage in guinea-pig spinal cord-spinal ganglia and in rat cerebella cultivated on collagen-coated coverslips in Leighton tubes. No change was seen in 22 cases. These data show that serum myelinotoxicity is low in MS - as compared with that of Experimental Allergic Encephalomyelitis. It appears a little specific phenomenon, the mechanism of which remains unclear. It can be easily assessed only in very sensitive culture techniques and is best measured by biochemical methods. This does not preclude the pathophysiological significance of the serum myelinotoxicity in MS. Supernatants of cerebro-spinal fluid (CSF) cell cultures in 10 MS patients caused no demyelination. Pooled concentrated supernatants of CSF cell cultures from 13 to 20 MS patients--containing from 7.3 to 11.7 micrograms IgG/ml gave no patent in vitro demyelination in 3 different experiments. The released products of CSF cell cultures in MS are not very toxic for myelin. However these experiments have to be repeated with more sensitive culture techniques, biochemical assay of myelinotoxicity and more concentrated CSF cultures supernatants.

Animals↗
PubMed1986

Stimulation of 2',3'-cyclic nucleotide 3'-phosphodiesterase in human lymphocytes by Robinia pseudoacacia lectin.

2',3'-Cyclic nucleotide 3'-phosphodiesterase (CNP) activity was studied in human peripheral blood lymphocytes. Incubation of human lymphocytes with optimum mitogenic concentrations of Robinia pseudoacacia lectin produced an increase in CNP activity. This increase was not detected before 24 h of incubation. Furthermore, whereas unfractionated lymphocytes exhibited activation of CNP, this was not observed in B and T cell subpopulations.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1986

Feeding frequency for lactating cows: effects on rumen fermentation and blood metabolites and hormones.

1. The present paper reports the effects on rumen fermentation and plasma metabolites and hormones of giving fixed rations of hay and high-cereal concentrates at different meal frequencies to lactating cows. In Expt 1 the total ration was given in two and twenty-four meals daily and in Expts 2-4 the concentrates were given in two and five or six meals and the hay in two meals daily. The diets contained 600-920 g concentrates/kg. 2. In Expt 1, minimum rumen pH was higher but mean pH was lower when cows were given their ration in twenty-four meals/d rather than two meals/d. 3. In all the experiments, the effects of increased meal frequency on the molar proportions of rumen volatile fatty acids (VFA) were small and not significant, although there was a general tendency for the proportion of acetic acid to increase and that of propionic acid to fall. Increasing the proportion of concentrates in the diet reduced the proportion of acetic acid and increased the proportions of propionic and n-valeric acids. 4. In Expt 3, more frequent feeding was found to reduce the concentration of non-esterified fatty acids in the blood, but changes in other metabolites were small and not significant. Increasing the proportion of concentrates in the diet reduced the concentrations of acetic acid and 3-hydroxybutyric acid and increased the concentrations of propionic acid and glucose. 5. The mean daily concentration of insulin in the blood was reduced by more frequent feeding of the higher-concentrate diet but not of the lower-concentrate diet. The concentration of glucagon also tended to fall with more frequent feeding. Increasing the proportion of concentrates in the diet increased the concentration of insulin. 6. More frequent feeding reduced the depression in milk-fat concentration caused by feeding the low-roughage diets. About three-quarters of the variation in milk-fat concentration could be related to changes in rumen VFA proportions, but the relations for the two meal frequencies had different intercepts although similar curves. The results suggest that milk-fat depression on low-roughage diets with twice-daily feeding was due to a change in rumen VFA proportions accompanied by elevated plasma insulin concentrations. The improvement in milk-fat concentration due to more frequent feeding could be explained partly by the small change in rumen VFA proportions and partly by a reduction in mean plasma insulin concentrations, but these mechanisms did not fully account for the milk-fat responses observed.

Animals↗
PubMed1985

IgG (Gm) allotypes and multiple sclerosis in a French population: phenotype distribution and quantitative abnormalities in CSF with respect to sex, disease severity, and presence of intrathecal antibodies.

The association of a given Gm allotype or phenotype with MS susceptibility, as previously described in some Caucasian populations, was not observed in a large French MS group, whether or not considering the possible influence of sex or disease severity. This result could be related to variations in geographical distribution of Gm alleles and MS susceptibility gene(s) or suggests the simultaneous involvement of Gm and other genetic system(s). In contrast, the corresponding CSFs exhibited already known MS-associated abnormalities of IgG1 (G1m) allotype contents, which therefore did not merely result from a Gm-associated MS susceptibility. These quantitative abnormalities were not sex dependent, but may fluctuate with MS severity. The G1m allotype levels in each CSF were not correlated with titers of various intrathecal antibodies but with the number of antibody specificities detected, a picture arguing for a polyclonal, non-antigen-specific activation of G1m allotype-producing B cells present in MS brain.

Antibodies↗
PubMed1985

HLA and multiple sclerosis: population and families study.

Association between HLA and multiple sclerosis (MS) was investigated at the population level on 100 MS patients genotyped for HLA-A, B, C, DR and Bf, Glo, and on 155 patients phenotyped for the same HLA antigens. Association between MS and DR2 was clearly confirmed, although its strength is rather weak. No other genetic marker could be related to the disease, no haplotype nor any allelic combination could be recognized as MS specific, and antigen genotype frequencies among the diseased could not ascertain the mode of inheritance, although dominance is very likely. Computer analysis between HLA, Bf, Glo and age of the patient, sex, age of onset and evolution of MS, impairment indexes, titres of anti-DNA and anti-measles antibodies in CSF did not show any interaction. Twenty sib pairs and two trios of MS were also studied; they showed no significant distortion with the random distribution of haplotypes. DR2 gene frequency, however, was significantly higher in sib pairs showing one or two haplotypes than in HLA different affected siblings. Three crossing-overs were identified which suggest where the HLA-linked MS susceptibility (MSS) gene could be located within the HLA segment, while other epistatic MSS genes or environmental factors are likely to be important.

Female↗
PubMed1985

HLA-DR-dependent variation of intrathecal IgG1 (Gm) allotype synthesis in multiple sclerosis.

Genetic susceptibility to multiple sclerosis (MS) in Caucasians was previously shown to be correlated to the presence of given alleles at the HLA-DR and Gm loci. We now demonstrate that the humoral immune response in MS central nervous system (CNS) is modulated by both loci: the levels of IgG1 subclass and IgG1 allotypes in cerebrospinal fluid of MS patients depend on both their Gm genotype and their HLA-DR2 or HLA-DR7 phenotype. That HLA-DR molecules may either participate in a preferential recruitment of IgG1 allotype-producing B cells in MS CNS or act after such a selective homing is discussed. These results demonstrate that both HLA and Gm loci are synergistically involved in the modulation of the humoral immune response.

Disease Susceptibility↗
PubMed1985

[Uveitis in acquired syphilis].

Syphilis is a well-established cause of uveal disease and is thought to be responsible for several distinct types of intraocular inflammation. Four cases of acquired syphilitic uveitis are reported. The diagnosis was essentially based on the clinical picture, the elimination of other possible causes, the results of reliable blood immunologic tests eg, the TPHA, FTA and Nelson tests, and the rapid response to penicillin therapy. Evaluation of anti-Treponema pallidum antibodies in the aqueous humor does not contribute to the diagnosis of syphilitic uveitis. Two cases needed large amounts of penicillin (total dosage, 440 million units). Oral steroids were used to control the associated inflammatory reaction and to prevent a Herxheimer reaction. All the patients responded well to therapy.

Adolescent↗
PubMed1984

Class II HLA-DC beta-chain DNA restriction fragments differentiate among HLA-DR2 individuals in insulin-dependent diabetes and multiple sclerosis.

HLA-DR2 allele is negatively associated with insulin-dependent diabetes and positively associated with multiple sclerosis (MS). A 2.2-kilobase-pair EcoRI DNA restriction fragment detected with a beta-chain HLA-DC cDNA probe was found to be strongly correlated with HLA-DR2 in the normal population, but was absent in HLA-DR2 insulin-dependent diabetic patients. This fragment was found in HLA-DR2 multiple sclerosis patients with the same frequency as in controls. A beta-chain HLA-DC 12-kilobase-pair BamHI fragment might differentiate multiple sclerosis patients from healthy individuals.

DNA Restriction Enzymes↗